SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e73cc9326251edf6edbbabdaa3feb106751b0e646c20b6a71f978ec688b8bd1d' 
  AND token = 'XloawQnSJqouh3nJ6cxAi+ZlFum4tP4FYmw2LYskkTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}